The broad goal of this research proposal is to better understand how semantic information is accessed and organized in unimpaired and brain-damaged individuals. Specifically it will evaluate the hypotheses that: (1) the concept of an object is distributed over semantic features, with concepts that share features having overlapping representations, and (2) these features are represented in the neural substrates that are invoked when we perceive and/or interact with the object. These claims will be investigated using three complementary methodologies. The first is an eye tracking paradigm that will help to establish the extent to which unimpaired individuals automatically activate a concept's various semantic attributes and the time course over which these attributes are activated. The second is an fMRI adaptation paradigm that will show both whether sensorimotor cortices corresponding to a concept's attributes are automatically activated when the concept is retrieved, and whether the neural representations of different but related concepts overlap. And the third methodology tracks the eye movements of brain-damaged patients who have difficulty accessing semantic knowledge, and uses the results to create voxel-based lesion-symptom maps linking semantic memory deficits to specific regions of brain damage. Gaining insight into these patients' deficits could lead to improved diagnoses and/or treatments. Together, these investigations will lead to a better understanding of how semantic information is organized, accessed and represented in normal subjects, and how semantic information degrades with various kinds of brain damage. [unreadable] [unreadable] [unreadable]